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Shelf-life/ expiry date for titanium powder

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frank72

Materials
Oct 16, 2006
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Does it make sense to define a self-live of titanium powder (TiCP) with an average grain size of 150 µm (mesh 90)? Powder is stored in airtight containers and after opening the container it will be used in days. For bar, sheet or other product forms nobody would think of it but for powder we have to consider giving a shelf life – or have good reasons not to do so.
 
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If your containers are truly air tight, and prevent significant humidity from affecting the state of the powder, I don't see why titaniaum (or any other high quality powderized metal) would have a shelf life.

Humidity is a concern depending on your end use - you need to prevent corrosion, and you may need to dry the powder before use depending on what process your powder is feedstock for.
 
I have no specific experience, but I highly doubt titanium powder will suffer any ill effects from humidity.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."
 
If the containers were purged and inert gas filled then your shelf life would be based on the seals.
The powder will be degraded by both oxygen and humidity.
We used to seal a powder far more reactive than Ti, and we found that we had to keep track of time as the container seals allowed some permeation of oxygen.

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An arbitrary shelf life is often given to products by manufacturers as a way to limit their legal liabilities. After the shelf life expires the customer cannot come back to them for for just about any reason.
 
We actually took containers of various ages, punctured them and took gas samples. The amount of oxygen in the containers shocked us. These had been filled by vacuum and Ar (99.999%) backfill.
I would suggest that you evaluate the performance of various samples with different levels of known exposure. Can you quantify degradation for material sitting in open air? You do have to be careful because temperature and humidity will matter.

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P.E. Metallurgy, consulting work welcomed
 
Hermetic seals are extremely hard to achieve IRL. We once had a 4-hr meeting about whether to include a overpressure bladder and what we needed to ensure no issues with thermal cycles on our box.

We built the box, filled it with nitrogen, and

it leaked out in about 5 minutes

TTFN (ta ta for now)
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